In the production of aluminum alloy products, aluminum ingots are melted, alloyed and cast into ingots which are subjected to a variety of forming operations such as rolling, extruding, milling, etc.
A particular concern involved in the process of casting the molten metal into ingots is avoiding the formation of metal oxides and preventing slag or dross from entering the ingot mold and adversely affecting the quality of the ingot.
The design and type of pouring equipment, pouring temperature and pouring techniques are major factors in preventing slag or dross from entering the ingot mold, in minimizing gas or air entrapment, and in minimizing turbulence or splashing. Excessive contact with the atmosphere caused by turbulence and/or splashing results in the formation of oxides of the molten metal which often float to the top of the molten metal and have to be removed by complicated ingot head skimmers and mechanical skim dams. Once cooled and solidified, ingots which have their surfaces contaminated with impurities (oxides) often have to be "scalped" whereby the outer, contaminated portion of the ingot is removed.
Conventional ingot casting processes utilize distribution or channel bags and spout socks which are designed to direct the flow of molten metal uniformly on the ingot head. The spout sock and distribution or channel bags are two separate assemblies which have to be properly aligned so that the molten metal can be transferred into the distribution or channel bag for uniform distribution into the ingot mold. In order to aid in uniformly distributing the molten metal into the ingot mold, it is known to include bottom diverters in the distribution or channel bags.
Various disadvantages are associated with the prior art distribution or channel bags including poor distribution of the molten metal and excessive turbulence which occurs when the molten metal is distributed into the ingot mold. Moreover, prior art bags promote oxide film build up on ingot head and the resulting heavy oxide film is released in the form of large patches that affect deleteriously the ingot rolling faces. Excessive turbulence can result in the undesirable formation of a thick oxide film or layer on top of the molten aluminum. The turbulence also can break portions of the oxide layer loose so they are carried to the sides of the ingot being formed where they form defects requiring scalping. Another appreciable disadvantage with the prior art bags is the problem of properly aligning the spout sock with the distribution or channel bag so as to avoid any unnecessary turbulence when transferring molten metal into the distribution or channel bag.
The present invention is an improvement over the prior art and provides for a novel distribution bag and spout sock assembly which minimizes turbulence in the molten metal while providing for more even distribution of the molten metal in the ingot mold as well as reducing the accumulation of oxide film on the ingot head.